For a link to the research by Imran Rasul and co-authors Brendon McConnell and Jérôme Adda:http://www.homepages.ucl.ac.uk/~uctpb...(sorry for not mentioning the other co-authors in the film. This is due to time constraints.)

'Cannabis is the most widely used illegal drug in the world, with many millions using it every day': There are an estimated 250 million drug users worldwide according to the UN. An estimated 162 million people used cannabis in 2004. The United Nations Office on Drugs Crime (UNODC) estimates that it accounted for around 80% of illegal drug use in 2004, suggesting that hundreds of millions of people use it regularly (see UN document here: http://www.unodc.org/pdf/WDR_2006/wdr...).

'Cannabis is less harmful to your health than alcohol or tobacco, according to government sponsored studies': In 2009, Professor David Nutt, the UK government's drug adviser was sacked for claiming that, among other things, cannabis was less dangerous than alcohol and tobacco. He also said that the chances of schizophrenia from cannabis use were around 1 in 5,0000. (See for example an article in the Guardian here: http://www.guardian.co.uk/politics/20...).

More on the Lambeth Cannabis Warning Pilot Scheme:Between 2001 and 2002, the London Borough of Lambeth 'depanalised' cannabis. This means that smoking cannabis was no longer a criminal offence. So long as cannabis was for personal use, the police would only remove the cannabis and they would issue a warning. There would be no arrests or prosecutions. The scheme was designed to save police time and money so they could focus on other crimes. (Link to a review of the Lambeth Cannabis Warning Pilot Scheme carried out by the Metropolitan Police Authority in 2002: http://www.mpa.gov.uk/committees/mpa/.... The police commander who brought in the scheme was, Brian Paddick who later ran for Mayor of London in 2008 and 2012 representing the Liberal Democrats. In the most recent election he offered to depanalise cannabis across London, see here: http://www.standard.co.uk/news/mayor/...).

Reports of children using cannabis in Lambeth from the Guardian, Telegraph among others: http://www.telegraph.co.uk/news/uknew... and http://www.guardian.co.uk/society/200.... (These newspapers weren't the only ones to report on the downsides of the scheme. The reason these two newspapers are mentioned in the film is because they are both well-respected newspapers known for having different political persuasions).